The present invention relates to a nerve guide comprising a shaped body made from a resorbable material.
Nerve guides of the kind described at the beginning are used for lesions of the nervous system in order to link the ends of damaged nerves and to bridge the gap between the two ends. In this way, the nerve guide provides the nerve fibers (axons) space to grow and ideally also provides protection against penetration by scar-forming, connective tissue cells (fibroblasts).
The two ends of the nerve guide then receive the two nerve stumps formed at the lesion and bridge the gap existing between them. The lumen of the nerve guide remaining between the nerve stumps specifies the direction for the regenerating axons and avoids any incorrectly-guided growth of these, a targeted regeneration being thereby promoted.
Biologically degradable or resorbable nerve guides are preferred for this as compared with non-resorbable, since after the nerve fibers have been restored or during this, the nerve guide breaks down and accordingly, in contrast to non-resorbable nerve guides, a further operation to remove the same is avoided, such an operation being necessary in some circumstances and itself in turn bringing the risk of damage to the nerve fibers. However, the stability of the resorbable nerve guide must be adjustable in respect of resorption mechanisms, which presents a challenge.
An object of nerve regeneration by means of nerve guides is restoration of motor and sensory functions as well as preventing incorrect guiding of nerve growth and formation of painful neuromas.
Regenerative medicine can up until now offer only unsatisfactory therapies for damage to nerve fibers of the nervous system. Although most adult neurones in principle have the capability of regenerating axons, only limited functional regeneration is found in the peripheral nervous system in the absence of assistance and as good as none at all in the central nervous system.
Reasons for these limitations are inter alia the loss of contact with the original nerve pathway and the formation of inhibiting scars.
An operative bridging of lesioned/inhibitory areas represents in principle a successful strategy for therapy, for which in practice however up to now autologous nerve transplants (mostly the sural nerve of the lower leg) were almost exclusively used.
The disadvantages connected with this such as morbidity in the donor region and limited availability have substantially stimulated development of synthetic nerve guides. Nerve guides in the form of hollow tubes have in more recent times been developed, made from different inert and resorbable, pure synthetic polymers and biological constituents, such as for example polysaccharides, collagen or specific cross-linked gelatin materials.